Camber for two way slab
Camber for two way slab
(OP)
Does anyone have any guidelines for the determination of camber for a two way slab. I have seen it done but I have not personally done it. I cannot find it in a code or any other reference that I had. I would have thought that the long-term calculated deflection value would be suitable at mid-slab.






RE: Camber for two way slab
Is there brickwork or other brittle finishes that will be damaged by deflection of the slab. In this case precamber will do nothing to reduce the deflection experienced by the brittle finishes.
If it is simply to reduce the visible long term deflection, normally you would not prrecamber by more than the short term dead load deflection.
RE: Camber for two way slab
So you think that the immediate dead load deflection would be enough? Is this stated in a code that you know of?..Or some other reference text?
thanks
Dave
RE: Camber for two way slab
RE: Camber for two way slab
Camber is not limited by any codes I know of. It's use is a "design/engineering judgement" decision, not something that needs to be limited by a code. Theoretically you can use any amount of camber you want as long as you maintain the deflected shape within the code limits at all times.
Having a flat condition at the time of application of live load is not a code judgement and is probably not achieveable unless you know the time of application of the live load and calculate deflections at that time due to the dead loads and long term effects. There is software that can do this for you But why would you want this?
The main use of precamber is to limit the long term visible deflection and ponding deflection on exposed slabs.
re the comment on thinner slabs, when precambering, the contractor should ensure that the slab thickness is maintained. Both the top and bottom surface of the member are supposed to be precambered. Simply precambering the bottom and maintaining a flat soffit is not logical.